19 Nortestosterone 17 [KLH]

Simultaneous separation of eleven steroid hormones and synthetic anabolics: progesterone, trenbolone acetate, melengestrol acetate, 17-beta-estradiol, 19-nortestosterone, fluoxymesterone, norethandrolone, 4-chloro-delta-1-methyl testosterone, clostebol acetate, 6-beta-hydroxymethandienone and oxymetholone, was performed on HPTLC plates, 10 x 10 cm, silicagel 60 F-254 (Merck) by horizontal elution in chloroform-acetone mobile phase. The investigated steroids were successfully visualised under UV light (254 nm), and after spraying with an ethanolic solution of p-toluenesulphonic acid. The efficacy of chromatographic system was checked using simulated real samples for some of the examined steroids, melengestrol acetate and trenbolone acetate, usually misused as growth promoters in cattle and stored unchanged in animal tissue.

The androgen receptor is an important pharmaceutical target for a variety of diseases. This paper presents an in silico/in vitro screening procedure to identify new androgen receptor ligands. The two-step virtual screening procedure uses a three-dimensional pharmacophore model and a docking/scoring routine. About 39,000 filtered compounds were docked with PLANTS and scored by Chemplp. Subsequent to virtual screening, 94 compounds, including 28 steroidal and 66 nonsteroidal compounds, were tested by an androgen receptor fluorescence polarization ligand displacement assay. As a result, 30 compounds were identified that show a relative binding affinity of more than 50% in comparison to 100 nM dihydrotestosterone and were classified as androgen receptor binders. For 11 androgen receptor binders of interest IC50 and K-i values were determined. The compound with the highest affinity exhibits a K-i value of 10.8 nM. Subsequent testing of the 11 compounds in a PC-3 and LNCaP multi readout proliferation assay provides insights into the potential mode of action. Further steroid receptor ligand displacement assays and docking studies on estrogen receptors alpha and beta, glucocorticoid receptor, and progesterone receptor gave information about the specificity of the 11 most active compounds. (C) 2014 Elsevier Masson SAS. All rights reserved.